How Colocation Providers Manage Energy Efficiency

April 17, 2012 2 Comments »
How Colocation Providers Manage Energy Efficiency

If your data center involves only company property (from the building to the infrastructure to the servers and other IT equipment), then you have complete control of every aspect of your implementation—energy efficiency is entirely up to you. But if you’re a colocation provider, then you are somewhat at the mercy of your customers, who may not have the same emphasis on energy efficiency. That doesn’t mean your facility is doomed to a life as an energy wastrel. Colocation providers can still take a number of steps to ensure efficiency, many of which are the same as those that other data centers take.

Focus on Infrastructure

Colocation providers, as such, are primarily focused on supplying data center infrastructure to customers—not so much on IT equipment and operations. As a result, this is the area in which they have the most control of their facilities’ energy efficiency. Infrastructure in this regard breaks down into two essential areas: cooling and power distribution. In a sense, colocation customers are supplying or purchasing machines that eat power (and network bandwidth) and leave behind heat. The colocation provider’s job is to provide that power and remove the waste heat. In addition to these primary functions, however, the colocation provider must also supply certain infrastructure elements to enable employees to do their work—the most obvious of these is lighting and environmental controls (heating and cooling).


The biggest drain on energy efficiency (particularly as measured by power usage effectiveness—PUE) is cooling. Every watt of energy consumed by the IT equipment (or by power distribution or any other part of the facility’s infrastructure) is turned into heat, and that heat must be removed if a constant temperature is to be maintained. The data center industry has been increasingly focusing on free cooling (air-side or water-side economization) as a much less energy-intensive means of keeping the facility cool, and colocation data centers can likewise exploit this option. In addition, ASHRAE’s recently expanded recommended and allowable temperature and humidity operation ranges enable even greater use of free cooling—even year round in many locations. Colocation data centers can thus simply follow the industry trend in this regard.

The complication, however, is selecting the appropriate operating temperature range. Not all of ASHRAE’s allowable operating ranges apply to all types of IT equipment; some manufacturers might void warranties for some of these ranges, meaning that not all colocation customers would be served by, say, the A2 operating range. The recommended range would be better suited to a wide variety of customers, but of course, it reduces the opportunity for free cooling in many regions. Locating the colocation data center in a cooler climate is one option, however, that increases free cooling potential.

Airflow management is another growing industry trend that colocation facilities can also exploit. Maintaining a larger temperature gradient by segregating warm air and cool air increases cooling efficiency, as well as energy efficiency. Hot aisle/cold aisle containment and the use of chimneys above cabinets and over CRACs or CRAHs are two means of increasing the temperature gradient. Computational fluid dynamics (CFD) analysis also enables facilities—particularly in the design stage—to eliminate hot spots and other thermal anomalies that can hinder efficiency.

Power Distribution

Avoiding losses between the utility entrance and the IT equipment is a critical means of maintaining high efficiency. Every percentage point of loss owing to inefficient UPS systems or distribution units means more wasted energy every moment. Even if you wish to avoid more-novel designs, such as those that involve DC power, you can still reduce power waste by implementing high-efficiency AC uninterruptible power supplies. In addition to cooling, this is where colocation data centers have the greatest control of their energy efficiency characteristics.

Peripheral Infrastructure

Chances are your facility has employees that must perform a variety of maintenance and operations functions. (The chances are actually pretty good—right around 100%.) The facility must provide adequate lighting, heating (in the winter) and cooling (in the summer), but this need not kill your efficiency. Lighting, in particular, is one area where significant improvements can often be made. Motion-sensing systems can turn off lights when employees are not present, eliminating the “oops, I forgot to turn the lights off” factor. For heating office areas in the winter, remember that your data center is filled with little heaters—why not put that heat to work whenever possible?


Some colocation providers can barely keep up with customer demand, but for those that are growing at a more controlled pace, a modular design approach avoids the installation of infrastructure that goes unused, leading to wasted capital and sometimes (depending on the infrastructure type) decreased efficiency. Building on pace with demand, rather than trying to forecast demand, enables efficiency on a number of fronts—including energy.

Don’t Leave Your Colocation Customers Out

Although colocation providers cannot necessarily control what types of IT equipment (specifically with relation to energy efficiency) customers use, they can nonetheless take steps to increase efficiency on this front. Offering customers resources on best practices for energy efficiency not only can lead to greater overall efficiency for the facility, but it can also yield cost savings for the customer and free up capacity in the colocation data center for other customers. Consider providing tips on virtualization, consolidation, leading-edge process technologies and other means of improving efficiency on the IT end.

Depending on how important efficiency is to your business, you might consider implementing customer rewards for efficiency practices. Some providers charge a premium for a highly efficient facility, since the customer is actually gaining more from the provider’s investment relative to a less efficient facility, although this may not be the greatest draw for customers. Whatever the case, providers can work with customers to improve energy efficiency—not all of this task need rest purely on the shoulders of the provider, although the provider has the onus of setting the overall tone of an emphasis on efficiency.


As infrastructure providers, colocation data centers must focus primarily on cooling, power distribution and peripheral infrastructure (like lighting) to maximize energy efficiency. The IT equipment, which is generally provided and controlled by customers, is out of the provider’s hands. But many of the modern industry practices with regard to areas like cooling and UPS systems apply equally to colocation providers: by implementing free cooling as much as possible and installing high-efficiency uninterruptible power supplies (UPSs) are tremendous steps toward a low PUE. Furthermore, a modular design approach allows providers to meet current demand and expand in the future as necessary, without the waste (in both capital and operational expenses) associated with implementing infrastructure beyond current needs.

But the data center need not pursue efficiency alone. By educating customers (and possibly instituting a reward policy for energy efficiency), the colocation provider can improve its overall efficiency while also reducing costs for the customer—a mutually beneficial approach. Thus, in many ways, managing energy efficiency is much the same for colocation data centers as for any other IT facility. But the primary difference—the customers—need not be a roadblock to an efficient facility.

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Photo courtesy of ChrisDag

About Jeff Clark

Jeff Clark is editor for the Data Center Journal. He holds a bachelor’s degree in physics from the University of Richmond, as well as master’s and doctorate degrees in electrical engineering from Virginia Tech. An author and aspiring renaissance man, his interests range from quantum mechanics and processor technology to drawing and philosophy.


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